This invention relates to a magnetic disc clutch mechanism for a magnetic disc apparatus of cartridge type.
A magnetic disc cartridge is composed of, as shown in FIG. 1; a magnetic disc 2 which is rotatively mounted in a plastic cartridge case 1; a disc hub 3 for also serving as an armature which is projected from an opening 1a of a bottom surface of the cartridge case 1 so as to be adapted to fix the rotation center of the magnetic disc 2; a latching lever 5, the back end of which is energized toward the inner bottom surface of the case 1 by virtue of a leaf spring 4, and the top end of which is energized against a flange portion 3a formed around the periphery of the disc hub 3 so as to fix the disc hub 3 to the inner bottom surface of the cartridge case 1.
In a conventional magnetic disc apparatus of cartridge type to drive this magnetic disc cartridge, the magnetic disc 2 is sustained within the case 1 in a floating manner described as follows. After fixing a spindle assembly to an inner bottom surface of a housing which defines a cartridge chamber and after inserting the cartridge in the chamber, if it is executed to close a door of the chamber, an operation of a link system and the like which is cooperative with the door makes the cartridge descend and thereby the bottom surface of the disc hub 3 is connected to a magnetic chuck of the spindle assembly. In addition, a release pin which is mounted on the inner bottom surface of the housing, projects into the cartridge and abuts to a guide pin 5a which is fixed to the latching lever 5 and further pushes the latching lever 5 upwardly. Thus the magnetic disc 2 is sustained within the case 1 in the floating manner.
However, this constitution has a drawback such that it becomes large-sided, because it needs to ascend and/or descend a horizontally supporting device of the cartridge which is inserted into the cartridge chamber itself.
Moreover, the cartridge should be inserted within the cartridge chamber with a little rattle in order to make it easy to insert the cartridge into the chamber. On the contary, if a distance between the cartridge and the spindle assembly is not large enough, the cartridge interferes with the spindle assembly in its inserting operation so that more elevation amount is needed. This results in that the device is much thicker.